Plant protein-based emulsions for the delivery of bioactive compounds

Enhanced interfacial stabilization of high internal phase emulsion using goose liver protein via ultrasonication fortified interfacial curcumin complexation

The interfacial complexation between goose liver protein (GLP) and oily dispersed curcumin in impacting the protein interfacial dynamics and high internal phase emulsions (HIPEs) stabilization was validated. Results from surface hydrophobicity, size, atomic force microscopy, and fluorescence quenching showed that pre-ultrasonication (100 W, 300 W and 500 W) conduced to pronounced heterogeneous hydrophobic interaction that elevated GLP adsorption and association at the interface. The synergistic curcumin complexation with medium ultrasonication (300 W+Cur) maximized GLP interfacial deposition and elasticity (11.58 and 32.80 mN/m for π10800 and Ed) due to most sufficient GLP unfolding. The HIPE for 300 W+Cur gave the highest network intersection with densely packed droplets from the lowest D [4,3] (38.17 ± 0.20 μm) while highest oil holding (91.91 %) and rheological stability. Turbiscan stability index, TBARS and fatty acid profile suggested that the 300 W+Cur displayed also the highest physiochemical stability (40 °C, 7 days) via sufficient oil enclosure and networking, as was also the case when oil polarity varied. This study reported firstly that the HIPEs stabilization could be tuned by interfacial GLP-curcumin complexation affinity (i.e., through protein pre-ultrasonication), which could potentiate GLP based HIPEs with tailored rheological and mechanical properties for applications.

Recent advances in the plant protein-polyphenol interactions for the stabilization of emulsions

Proteins from plant sources including legumes, cereals and oilseeds are gaining attention due to their suitability for sustainable production, functionality, and positive consumer perception. On the other hand, polyphenols (PPs) are receiving considerable attention as natural ingredients in the human diet due to their potent antioxidant and anti-inflammatory properties. Recent studies indicate that the emulsifying properties of plant proteins (PLPs) can be improved after modification through covalent and/or non-covalent interactions with PPs due to the changes in the conformation and/or the surface chemistry of the proteins. Complexes formed between PLPs-PPs can serve as innovative ingredients for developing novel food products with modified textural properties. Also, Pickering emulsions, multiple emulsions, multilayer emulsions, nanoemulsions, and high internal phase emulsions can be stabilized by such systems to deliver bioactive compounds. This paper reviews the most recent research on the PLP-PP interactions and their role in the stabilization of various emulsion-based systems. A special emphasis is given to modifying the structure and functionality of PLPs and PPs. The challenges and opportunities of applying PLP-PP interactions in emulsion-based systems are also highlighted.

Quercetin encapsulation and release using rapid CO2-responsive rosin-based surfactants in Pickering emulsions

Emulsion-based delivery systems are extensively employed for encapsulating functional active ingredients, protecting them from degradation, and enhancing bioavailability and release efficiency. Here, a CO2-responsive surfactant synthesized from rosin displays rapid responsiveness to CO2 at room temperature, transitioning reversibly switches between active and inactive states multiple times. The dual tertiary amines on the rosin rigid structure contributes to its CO2 sensitivity. When in its active cationic form, in conjunction with silica nanoparticles, it exhibits desired Pickering emulsification performance across various oil phases. In the Pickering emulsion loaded with quercetin, the encapsulation efficiency and loading efficiency reached 80.50% and 0.69%, respectively, with stability lasting at least 30 days. The system provides robust protection for quercetin against external factors, such as UV and heat, revealing sustained release effects. This study investigated the potential of using rosin-based CO2-responsive surfactants alongside nanoparticles to design stable Pickering emulsion systems for active substance encapsulation and sustained release.

High internal phase Pickering emulsions stabilized by Zein-hyaluronic acid conjugate particles and their application in active substances protection

In recent years, active substances have been extensively applied in the fields of food, cosmetics, and pharmaceuticals. However, their preservation and transportation have posed challenges due to issues such as oxidation and photodegradation. This study proposes a method for synthesizing Zein-Hyaluronic Acid (Zein-HA) conjugate particles via the Schiff base reaction, utilizing these conjugate particles to encapsulate and protect active substances within a stable emulsion system. Compared to zein, the modified conjugate particles exhibit significantly improved dispersibility, amphiphilicity, interfacial affinity, and emulsifying properties. Consequently, these particles are capable of stabilizing high internal phase Pickering emulsions with an oil phase volume fraction of up to 80 (v/v)%, thereby enabling the carriage of a higher load of active components. Furthermore, the prepared emulsions demonstrate excellent storage stability, resistance to ionic strength (250-2000 mM NaCl), and outstanding antioxidative characteristics. Moreover, after 8 h of UV light exposure, the retention rates of the active substances (curcumin, astaxanthin, and resveratrol) exceed 60 %. Therefore, these emulsions hold substantial potential to be applied as a carrier system in the food, cosmetics, and pharmaceutical industries.

Advances of protein-based emulsion gels as fat analogues: Systematic classification, formation mechanism, and food application

Fat plays a pivotal role in the appearance, flavor, texture, and palatability of food. However, excessive fat consumption poses a significant risk for chronic ailments such as obesity, hypercholesterolemia, and cardiovascular disease. Therefore, the development of green, healthy, and stable protein-based emulsion gel as an alternative to traditional fats represents a novel approach to designing low-fat food. This paper reviews the emulsification behavior of proteins from different sources to gain a comprehensive understanding of their potential in the development of emulsion gels with fat-analog properties. It further investigates the emulsifying potential of protein combined with diverse substances. Then, the mechanisms of protein-stabilized emulsion gels with fat-analog properties are discussed, mainly involving single proteins, proteins-polysaccharides, as well as proteins-polyphenols. Moreover, the potential applications of protein emulsion gels as fat analogues in the food industry are also encompassed. By combining natural proteins with other components such as polysaccharides, polyphenols, or biopolymers, it is possible to enhance the stability of the emulsion gels and improve its fat-analog texture properties. In addition to their advantages in protecting oil oxidation, limiting hydrogenated oil intake, and delivering bioactive substances, protein-based emulsion gels have potential in food 3D printing and the development of specialty fats for plant-based meat.

Emulsification and stabilisation technologies used for the inclusion of lipophilic functional ingredients in food systems

Food industry is increasingly using functional ingredients to improve the food product quality. Lipid-containing functional ingredients are important sources of nutrients. This review examines the current state of emulsification and stabilisation technologies for incorporating lipophilic functional ingredients into food systems. Lipophilic functional ingredients, such as omega-3 fatty acids, carotenoids, and fat-soluble vitamins, offer numerous health benefits but present challenges due to their limited solubility in water-based food matrices. Emulsification techniques enable the dispersion of these ingredients in aqueous environments, facilitating their inclusion in a variety of food products. This review highlights recent advances in food emulsion formulation, emulsification methods and stabilisation techniques which, together, improve the stability and bioavailability of lipophilic compounds. The role of various emulsifiers, stabilizers, and encapsulation materials in enhancing the functionality of these ingredients is also explored. Furthermore, the review discusses different stabilisation techniques which can yield in emulsion in a solid or liquid state. By providing a comprehensive overview of current technologies, this review aims to guide future research and application in the development of functional foods enriched with lipophilic ingredients.

Effects of the Combination of Protein in the Internal Aqueous Phase and Polyglycerol Polyricinoleate on the Stability of Water-In-Oil-In-Water Emulsions Co-Encapsulating Crocin and Quercetin

This study aimed to diminish the reliance on water-in-oil-in-water (W/O/W) emulsions on the synthetic emulsifier polyglycerol polyricinoleate (PGPR). Considering the potential synergistic effects of proteins and PGPR, various protein types (whey, pea and chickpea protein isolates) were incorporated into the internal aqueous phase to formulate W/O/W emulsions. The effects of the combination of PGPR and protein at different ratios (5:0, 4:1, 3:2, 1:1 and 2:3) on the stability and encapsulation properties of W/O/W emulsions co-encapsulating crocin and quercetin were investigated. The findings indicated that the combination of PGPR and protein resulted in a slight reduction in the encapsulation efficiency of the emulsions, compared to that of PGPR (the control). Nonetheless, this combination significantly enhanced the physical stability of the emulsions. This result was primarily attributed to the smaller droplet sizes and elevated viscosity. These factors contributed to increased retentions of crocin (exceeding 70.04%) and quercetin (exceeding 80.29%) within the emulsions after 28 days of storage, as well as their improved bioavailability (increases of approximately 11.62~20.53% and 3.58~7.98%, respectively) during gastrointestinal digestion. Overall, combining PGPR and protein represented a viable and promising strategy for reducing the amount of PGPR and enhancing the stability of W/O/W emulsions. Notably, two plant proteins exhibited remarkable favorability in this regard. This work enriched the formulations of W/O/W emulsions and their application in the encapsulation of bioactive substances.